Dixon 52112 Lumber Marking Crayons, Soft Blue, 4-1/2 x 1/2" Hex, Pack of 12 Graphite lumber crayons measure 4-1/2 x 1/2 inches Crayons last up to 10 times longer than ordinary molded wax crayons Fade-proof, water-proof and smear-proof Use on wet (green) lumber or dry wood, metal, concrete and most other surfaces Box of 12 crayons